Mirrors have been known to man for many centuries. The mirrors made by the ancient Greeks and Romans were mostly made from polished bronze, but glass mirrors were also known. During the middle ages, a process for backing glass with a thin layer of silver and steel was developed.
Today, mirrors are used in a variety of wide ranging applications such as astronomy, space ships, solar devices, vehicles, microscopes, satellite communication devices and medicine. One of the best-known applications for mirrors consists of their use on motor vehicles.
Motor vehicles require mirrors in order to provide the driver or operator of the vehicle with a field of view behind and beside the vehicle. This is done for safety purposes since most vehicles, due to structural obstructions, have “blind spots” which prevent the driver from seeing any object that may come near the front, rear or sides of the vehicle. For years, the automobile designers have attempted to eliminate these blind spots when designing vehicles. Unfortunately, this objective can never be achieved because of the design of the motor vehicle. Thus, it has been found necessary to mount mirrors in and around the vehicle to enhance the field of view of the driver.
Many of the aforementioned prior art mirrors have had success in reducing “blind spots” in front of large vehicles, such as school buses. The National Safety Council has reported that 58,000 annual school bus accidents occurred nationally in 1977 and 1978 with approximately 165 fatalities per year. A Kansas Department of Transportation study of these national school bus fatalities pinpoints the contributing factors. From 1975 through 1978, 73 percent of the fatalities were among homeward bound pupils; 60 percent of the pupils were killed by the bus itself; and 47 percent were 5 and 6 years old. These statistics indicate that enhancing the driver's view in front of and around the vehicle could reduce these fatalities.
One mirror that has been designed to reduce blind spots in front of a vehicle such as a bus is a cross view mirror. Cross view mirrors have been designed and mounted to the front corners of the bus to provide the driver with visual access to the areas in front and sides of the bus that are hidden from direct view. Currently available cross view mirrors are required to see a particular forward, rightward and leftward visual orientation in front of school buses as mandated by FMVSS (Federal Motor Vehicle Safety Standard) 111. Under FMVSS 111, the school bus builder certifies mirror compliance using the eye ellipses of a 25th percentile women driver when the school bus is sold.
When cross view mirrors were first introduced to the school bus industry, the front end of the bus was basically flat and had headlights that were on the same plane as the front grill. Recently, in an effort to improve aerodynamics, the headlights have been moved aft of the front grill and wrapped over the top of the fender. These changes sometimes create headlight glare in the driver's eyes reflecting from the mirrored surface of cross view mirrors.
Attempts to combat headlight glare have focused on adjustments to the mirror height at the intersection point that comply with FMVSS 111. However, increasing the mirror height often makes for more difficult bracing, potential increases in vibration, and additional stresses on the vehicle hood at mounting points. This additional mirror height moves the blind spot in the driver's natural, forward line of site. Finally, the additional mirror height likely does not solve the headlight glare problem and is not aesthetically pleasing.